<template>
  <div id="app">
    <transition name="router-fade" mode="out-in">
      <keep-alive>
        <router-view v-if="$route.meta.keepAlive"></router-view>
      </keep-alive>
    </transition>
    <transition name="router-fade" mode="out-in">
      <router-view v-if="!$route.meta.keepAlive"></router-view>
    </transition>
  </div>
</template>

<script>
export default {
  name: 'App'
  // created () {
  //   // 防止刷新页面vuex数据丢失
  //   // 在页面加载时读取sessionStorage里的状态信息
  //   if (sessionStorage.getItem('store')) {
  //     this.$store.replaceState(Object.assign({}, this.$store.state, JSON.parse(sessionStorage.getItem('store'))))
  //   }
  //   // 在页面刷新时将vuex里的信息保存到sessionStorage里
  //   window.addEventListener('beforeunload', () => {
  //     sessionStorage.setItem('store', JSON.stringify(this.$store.state))
  //   })
  // }
}
</script>

<style lang="stylus" scoped>
  .router-fade-enter-active, .router-fade-leave-active {
    transition: opacity .3s;
  }
  .router-fade-enter, .router-fade-leave-active {
    opacity: 0;
  }
</style>
